Publications

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2014
Širović, A, Johnson SC, Roche LK, Varga LM, Wiggins SM, Hildebrand JA.  2014.  North Pacific right whales (Eubalaena japonica) recorded in the northeastern Pacific Ocean in 2013. Marine Mammal Science. :n/a-n/a.   10.1111/mms.12189   AbstractWebsite
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2018
Varga, LM, Wiggins SM, Hildebrand JA.  2018.  Behavior of singing fin whales Balaenoptera physalus tracked acoustically offshore of Southern California. Endangered Species Research. 35:113-124.   10.3354/esr00881   AbstractWebsite

Fin whales Balaenoptera physalus produce stereotyped low-frequency calls (1530 Hz) that can be detected at great ranges and are considered song when produced in a repeated temporal pattern. These calls, referred to as 20 Hz calls, were localized and tracked using a 1 km aperture array of 4 passive acoustic recorders at approximately 800 m depth northwest of San Clemente Island, offshore of Southern California, USA, for 4 continuous weeks during late fall 2007. A total of 1454 calls were localized over the recording period. The average (+/- SD) estimated source sound pressure level was 194.8 +/- 0.2 dB(pp) re 1 mu Pa-2 at 1 m (where pp is peak-to-peak) and 180.9 +/- 0.2 dB(rms) re 1 mu Pa at 1 m (where rms is root mean square). The majority of these calls were in the form of a doublet song pattern, with average inter-pulse intervals of 13 and 18 s. These tracks are the first to be reported for transiting solitary singing fin whales using passive acoustic monitoring techniques. Acoustic tracking of fin whales provides insight into the ecology and behavior of this endangered species as well as vocal behaviors, which are important when studying the potential impact of anthropogenic noise. Call source sound pressure level, along with calling behavior, provides important parameters required for population density estimation. Furthermore, studying fin whale song patterns may aid in distinguishing different subpopulations.